The present disclosure relates to a cleaning device which collects a toner and other residue having remained on a surface of an image carrier, such as an intermediate transferring belt and an image forming apparatus including this cleaning device.
Conventionally, an image forming apparatus, such as a copying machine, a printer, a facsimile machine or a multifunction peripheral, is configured to transfer to a sheet a toner image carried onto an image carrier, such as an intermediate transferring belt or a photosensitive drum. Such an image forming apparatus may include a cleaning device which catches a residue, such as a residual toner or sheet powder, having adhered to a surface of the image carrier after the toner image has been transferred.
The cleaning device includes, for example, a rotating brush (a fur brush), a collecting roller, a cleaning blade, and a collecting screw. In addition, the rotating brush coming into contact with the surface of the image carrier catches the residue having adhered to the surface of the image carrier, whereas the collecting roller coming into contact with the rotating brush collects the residue having been caught by the rotating brush. The cleaning blade abuts against the collecting roller in a counter direction with respect to rotation of the collecting roller, and then, drops the residue collected by the collecting roller to the collecting screw.
For example, the cleaning device may be configured so that an elastic blade (a cleaning blade) scrapes the residual toner from the image carrier, and then, drops the scraped residual toner to a residual toner collecting member (a collecting screw). In this cleaning device, at an upstream side from an abutment part of the cleaning blade and the image carrier in a rotation direction of the image carrier, a sealing member is disposed while being in abutment against the surface of the image carrier, thereby preventing the residual toner from accumulating or leaking to a side of the image carrier side.
In a case where the sealing member is applied to the cleaning device including the collecting roller mentioned above, the sealing member is provided so as to abut against the collecting roller against which the cleaning blade has abutted. However, in this case, in order to make the sealing member excellently act, it is necessary to construct the cleaning device in consideration of parameters, such as a material and surface roughness of the collecting roller, as well as an electrostatic friction coefficient of the sealing member.
For example, in a case where the surface roughness of the collecting roller is extremely low, clogging of the residue, such as the toner or the sheet powder, between the collecting roller and the sealing member easily occurs, and moreover, it becomes difficult for the collecting roller to collect the adhered matter having caught by the rotating brush. Alternatively, in a case where the surface roughness of the collecting roller is extremely high, toner scraping property by the cleaning blade may be deteriorated.
Incidentally, the scraping property of the cleaning blade is deteriorated more, as toner sphericity is closer to a spherical shape. The scraping property of the cleaning blade can make excellent by lowering the surface roughness of the collecting roller irrespective of the toner sphericity. However, in such a case, as mentioned above, the clogging of the residue may occur between the collecting roller and the sealing member.
Also, when the collecting roller is made of a material of higher adhesive force, whereby even in a case where the surface roughness of the collecting roller is lowered, the clogging of the residue between the collecting roller and the sealing member may be released. However, if the surface roughness of the collecting roller has been extremely lowered in accordance with the toner sphericity, close contact property between the collecting roller and the cleaning blade increases and it is feared to cause blade turning-up of the cleaning blade and other failures.